The Australian Taxation Office was closing in and, police allege, the architects of the syndicate had just been forced to pay $5 million to disgruntled members who threatened to publicly expose the scam.

The alleged ringleaders, including Adam Cranston, son of ATO deputy commissioner Michael Cranston, had a crisis meeting on the 46th floor of the offices of Clemenz Lawyers in Sydney to discuss how to foil any tax office investigation.

Their plan was simple: they would pin the fraud on a former associate, Peter Leslie Larcombe, a flashy Sydney businessman with deep links to the Comancheros bikie gang.

According to a police statement of facts, at a subsequent meeting, alleged syndicate lawyer Dev Menon told Adam Cranston's sister, Lauren that, "if they are questioned at a future time, they should say that 'Peter ran the whole thing'." They called it a "failsafe".

The appeal of this scheme was obvious: Larcombe was dead. Six month earlier, he had leapt to his death from a parking garage at Los Angeles International Airport. The Los Angeles coroner insisted it was an "open and shut case of suicide", a source said.

Large, with an air of menace, but disarmingly intelligent, Larcombe has been described by one close associate as a "rugby player in a suit". In meetings, he would sit silently at the back of the room with his arms crossed to put others on edge. "Everyone thought he was just the thug in the corner. He rarely spoke," the source says, "but he was the smart one".

The 38-year-old private school boy also had a wild side, including a taste for cocaine, fast cars and boasting about his links to bikies. "He was a risk-taker, he had no concept of consequence," according to a former friend.

Experiencing business problems of his own, the friend had once asked Larcombe how he dealt with similar problems. "We just call in the bikies," Larcombe told him.

Corporate records show Larcombe had business links with Adam Cranston, who is facing criminal charges.

In 2011, they teamed up to form a business called Aventis Partners. Cranston left the business a year later, but Larcombe apparently remained a director until seven months after his death. Christopher James Guillan, who has also been charged in the Plutus case, was a shareholder.

Larcombe also appears to have pioneered the business model that Plutus subsequently exploited to make its co-conspirators rich.

He founded a payroll company in 2014 called Keystone Pay, which promised cheap payroll services. He almost immediately palmed it off to an apparently unrelated director - also consistent with the Plutus script. Keystone collapsed last year owing more than $6.9 million to the tax office.

In 2014, Larcombe relocated to Dubai, but he made business and personal trips back to Australia. His death came just before a return journey to the Gulf state in August 2016.

Fairfax Media understands Larcombe jumped from the parking garage at LAX in front of his wife and two children after saying he did not want to return to Dubai.

Sources say at that time Larcombe had been under increasing pressure from members of a western Sydney crime family who have an extensive property portfolio in Sydney's inner-city and eastern suburbs.

Larcombe had previously had dealings with the family, including one member who has served more than a decade in prison for a south-western Sydney shooting murder. They acted as business partners and hired muscle for Larcombe.

But his move to Dubai, said to have been sparked by the multimillion-dollar tax bill owed to the ATO, angered the crime family. It's understood they believed the move was actually about cutting them out of a deal, and that he now owed money to them.

The crime family knew people Larcombe was dealing in Dubai, who had links to Sydney Comanchero bikies, and they began putting pressure on Larcombe to pay up.

Rumours about his shocking end filtered back to Australia as claims that he'd died in mysterious circumstances.

Larcombe was just one of the syndicate's "fail safes": lawyer Dev Menon also allegedly suggested the Plutus conspirators lay the blame at the feet of another lawyer, Sevag Chalabian, who was already infamous for being the man who set up the tangle of trusts for corrupt NSW politician Eddie Obeid.

As Thursday's multiple arrests demonstrate, no matter how convenient a patsy Peter Larcombe seemed to be, the scheme to lay blame at his feet was destined to fail.

Lifeline 131 114

MensLine 1300 789 978

Beyondblue 1300 224 636

cvedelago@theage.com.au